Commissure attachment feature for prosthetic heart valve

ABSTRACT

A prosthetic heart valve includes a collapsible and expandable stent having a proximal end, a distal end, an annulus section adjacent the proximal end and an aortic section adjacent the distal end, the stent including a plurality of struts. A plurality of commissure features is disposed on the stent and coupled to selected ones of the struts, each commissure feature including a body having a proximal end and a distal end, and at least one eyelet in the body. The heart valve further includes a collapsible and expandable valve assembly including a plurality of leaflets. At least one leaflet is connected to the at least one eyelet and to at least one of the selected ones of the struts via a suture pattern.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of the filing date of U.S.Provisional Patent Application No. 61/666,353 filed Jun. 29, 2012, thedisclosure of which is hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to heart valve replacement and, inparticular, to collapsible prosthetic heart valves. More particularly,the present invention relates to collapsible prosthetic heart valveshaving superior commissure feature attachments.

Prosthetic heart valves that are collapsible to a relatively smallcircumferential size can be delivered into a patient less invasivelythan valves that are not collapsible. For example, a collapsible valvemay be delivered into a patient via a tube-like delivery apparatus suchas a catheter, a trocar, a laparoscopic instrument, or the like. Thiscollapsibility can avoid the need for a more invasive procedure such asfull open-chest, open-heart surgery.

Collapsible prosthetic heart valves typically take the form of a valvestructure mounted on a stent. There are two types of stents on which thevalve structures are ordinarily mounted: a self-expanding stent and aballoon-expandable stent. To place such valves into a delivery apparatusand ultimately into a patient, the valve must first be collapsed orcrimped to reduce its circumferential size.

When a collapsed prosthetic valve has reached the desired implant sitein the patient (e.g., at or near the annulus of the patient's heartvalve that is to be replaced by the prosthetic valve), the prostheticvalve can be deployed or released from the delivery apparatus andre-expanded to full operating size. For balloon-expandable valves, thisgenerally involves releasing the valve, assuring its proper location,and then expanding a balloon positioned within the valve stent. Forself-expanding valves, on the other hand, the stent automaticallyexpands as the sheath covering the valve is withdrawn.

Despite the various improvements that have been made to collapsibleprosthetic heart valves, conventional valves and systems suffer fromsome shortcomings. For example, conventional prosthetic valves may failat high stress regions including the leaflet-commissure featurejunction. Failure may, for example, include tearing of the suturesand/or the leaflets. To reduce the risk of failure, the optimal valvewould more adequately secure the leaflets to the stent without addingunwanted bulk to the overall structure.

There therefore is a need for further improvements to collapsibleprosthetic heart valves, and in particular, self-expanding prostheticheart valves. Among other advantages, the present invention may addressone or more of these needs.

SUMMARY OF THE INVENTION

In some embodiments, a prosthetic heart valve includes a collapsible andexpandable stent having a proximal end, a distal end, an annulus sectionadjacent the proximal end and an aortic section adjacent the distal end,the stent including a plurality of struts. A plurality of commissurefeatures may be disposed on the stent and coupled to selected ones ofthe struts, each commissure feature including a body having a proximalend and a distal end, and at least one eyelet in the body. The valvefurther includes a collapsible and expandable valve assembly, includinga plurality of leaflets, at least one of the leaflets being connected toat least one eyelet and to at least one of the selected ones of thestruts via a suture pattern.

In some examples, selected ones of the struts includes two strutscoupled to the distal end of the body, and the at least one leaflet isconnected to the two struts. Selected ones of the struts may alsoinclude two struts coupled to the proximal end of the body, and the atleast one leaflet is connected to the two struts. Selected ones of thestruts may further includes two additional struts coupled to theproximal end of the body, and the at least one leaflet is furtherconnected to the two additional struts.

In some examples, each body has two eyelets and a central rib formedbetween the two eyelets. The suture pattern may include loops of suturearound the central rib. The suture pattern may include four loops ofsuture around the central rib. Two leaflets may be connected to eachcommissure feature. The suture pattern may be symmetrical about acentral axis passing through the body between the proximal and distalends of the body.

In some embodiments, a method of assembling a prosthetic heart valveincludes providing a collapsible and expandable stent having a proximalend, a distal end, an annulus section adjacent the proximal end and anaortic section adjacent the distal end, the stent include a plurality ofstruts and a plurality of commissure features disposed on the stent andcoupled to selected ones of the struts, each commissure featureincluding a body having a proximal end and a distal end, and at leastone eyelet in the body. A collapsible and expandable valve assembly iscoupled to the stent, the valve assembly including a plurality ofleaflets, and the coupling step including connecting at least one of theleaflets to the at least one eyelet and to at least one of the selectedones of the struts via a suture pattern.

In some examples, selected ones of the struts include two struts coupledto the distal end of the body, and the coupling step includes connectingthe at least one leaflet to the two struts. Selected ones of the strutsmay also include two struts coupled to the proximal end of the body, andthe coupling step includes connecting the at least one leaflet to thetwo struts. Selected ones of the struts may further include twoadditional struts coupled to the proximal end of the body, and thecoupling step further includes connecting the at least one leaflet tothe two additional struts. The coupling step may include connecting twoleaflets to each commissure feature. The coupling step may includecoupling the at least one leaflet to the body using a suture patternthat is symmetrical about a central axis passing through the bodybetween the proximal and distal ends of the body.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present invention are described herein withreference to the drawings, wherein:

FIG. 1 is a partial side elevational view of a prosthetic heart valveincluding a valve assembly and a stent;

FIG. 2A is an end view of a prosthetic heart valve as seen from theaortic sinus toward the heart and the native valve annulus, the valvehaving a circular configuration;

FIG. 2B is an end view of a prosthetic heart valve as seen from theaortic sinus toward the heart and the native valve annulus, the valvehaving an elliptical configuration;

FIG. 3 is a partial side elevational view of the prosthetic heart valveof FIG. 1 depicting areas of high stress on the valve assembly;

FIG. 4 is an enlarged top perspective view of wear along a portion ofthe collapsible prosthetic heart valve at the suture junction with thecuff;

FIG. 5 is an enlarged schematic side view of a commissure featureaccording to the present invention;

FIGS. 6A and 6B are enlarged schematic side views of a suture patternattaching leaflets to a commissure feature as shown from the ablumenalside and the lumenal side of the valve, respectively; and

FIG. 6C is a highly enlarged, schematic side view showing the suturepattern coupling the leaflets to the commissure feature of FIGS. 6A and6B.

Various embodiments of the present invention will now be described withreference to the appended drawings. It is to be appreciated that thesedrawings depict only some embodiments of the invention and are thereforenot to be considered limiting of its scope.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the term “proximal,” when used in connection with aprosthetic heart valve, refers to the end of the heart valve closest tothe heart when the heart valve is implanted in a patient, whereas theterm “distal,” when used in connection with a prosthetic heart valve,refers to the end of the heart valve farthest from the heart when theheart valve is implanted in a patient.

FIG. 1 shows a collapsible prosthetic heart valve 100 according to anembodiment of the present disclosure. The prosthetic heart valve 100 isdesigned to replace the function of a native aortic valve of a patient.Examples of collapsible prosthetic heart valves are described inInternational Patent Application Publication No. WO/2009/042196; U.S.Pat. No. 7,018,406; and U.S. Pat. No. 7,329,278, the disclosures of allof which are hereby incorporated herein by reference. As discussed indetail below, the prosthetic heart valve has an expanded condition and acollapsed condition. Although the invention is described herein asapplied to a prosthetic heart valve for replacing a native aortic valve,the invention is not so limited, and may be applied to prosthetic valvesfor replacing other types of cardiac valves.

The prosthetic heart valve 100 includes a stent or frame 102, which maybe wholly or partly formed of any biocompatible material, such asmetals, synthetic polymers, or biopolymers capable of functioning as astent. Suitable biopolymers include, but are not limited to, elastin,and mixtures or composites thereof. Suitable metals include, but are notlimited to, cobalt, titanium, nickel, chromium, stainless steel, andalloys thereof, including nitinol. Suitable synthetic polymers for useas a stent include, but are not limited to, thermoplastics, such aspolyolefins, polyesters, polyamides, polysulfones, acrylics,polyacrylonitriles, polyetheretherketone (PEEK), and polyaramides. Thestent 102 may have an annulus section 110, an aortic section (not shown)and a transition section (not shown) disposed between the annulussection and the aortic section. Each of the annulus section 110, theaortic section and the transition section of the stent 102 includes aplurality of cells 112 connected to one another around the stent. Theannulus section 110, and the aortic section of the stent 102 may includeone or more annular rows of cells 112 connected to one another. Forinstance, the annulus section 110 may have two annular rows of cells112. When the prosthetic heart valve 100 is in the expanded condition,each cell 112 may be substantially diamond shaped. Regardless of itsshape, each cell 112 is formed by a plurality of struts 114. Forexample, a cell 112 may be formed by four struts 114.

The stent 102 may include commissure features 116 connecting at leasttwo cells 112 in the longitudinal direction of the stent 102. Thecommissure features 116 may include eyelets for facilitating thesuturing of a valve assembly 104 to the sent 102.

The prosthetic heart valve 100 also includes a valve assembly 104attached inside the annulus section 110 of the stent 102. United StatesPatent Application Publication No. 2008/0228264, filed Mar. 12, 2007,and United States Patent Application Publication No. 2008/0147179, filedDec. 19, 2007, the entire disclosures of both of which are herebyincorporated herein by reference, describe suitable valve assemblies.The valve assembly 104 may be wholly or partly formed of any suitablebiological material or polymer. Examples of biological materialssuitable for the valve assembly 104 include, but are not limited to,porcine or bovine pericardial tissue. Examples of polymers suitable forthe valve assembly 104 include, but are not limited to, polyurethane andpolyester. In at least some examples, portions of valve assembly 104, acuff and the suture used may include an ultra high molecular weightpolyethylene, such as FORCE FIBER®.

The valve assembly 104 may include a cuff 106 disposed on the lumenalsurface of annulus section 110, on the ablumenal surface of annulussection 110, or on both surfaces, and the cuff may cover all or part ofeither or both of the lumenal and ablumenal surfaces of the annulussection. The cuff 106 and/or the sutures used to attach the valveassembly 104 to stent 102 may be formed from or includeultra-high-molecular-weight polyethylene. FIG. 1 shows cuff 106 disposedon the lumenal surface of annulus section 110 so as to cover part of theannulus section while leaving another part thereof uncovered. The cuff106 may be attached to strut 102 by one or more strings or suturespassing through the cuff and around selected struts 114 of the stent.The valve assembly 104 may further include a plurality of leaflets 108which collectively function as a one-way valve. A first edge 122 of eachleaflet 108 may be attached to the stent 102 between two adjacentcommissure features 116 by any suitable attachment means, such assuturing, stapling, adhesives or bonding via laser, ultrasound or heatas well as any other suitable method. For example, the first edge 122 ofeach leaflet 108 may be sutured to the stent 102 by passing strings orsutures through the cuff 106 of the valve assembly 104. The leaflets 108may be attached to the stent 102 along at least some struts 114 of thestent and through the eyelets in the commissure features 116 to enhancethe structural integrity of the valve assembly 104. A second or freeedge 124 of each leaflet 108 may coapt with the corresponding free edgesof the other leaflets, thereby enabling the leaflets to functioncollectively as a one-way valve.

As shown in FIG. 1, at least one leaflet 108 may be attached to thestent 102 so that its first edge 122 is disposed substantially alongspecific struts 114 a, 114 b, 114 c, 114 d, 114 e and 114 f located inthe annulus section 110 of the stent. That is, the edge 122 ispositioned in substantial alignment with struts 114 a, 114 b, 114 c, 114d, 114 e, and 114 f. Struts 114 a, 114 b, and 114 c may be connected toone another in substantially end-to-end fashion diagonally along threecells 112, beginning with an end of the strut 114 a connected to acommissure feature 116 and ending with an end of strut 114 c connectedto an end of strut 114 d. Struts 114 c and 114 d are part of the samecell 112 and may collectively define a substantially right angle betweenthem. Struts 114 d, 114 e, and 114 f may be connected to one another insubstantially end-to-end fashion diagonally along three cells 112,beginning with an end of the strut 114 f connected to a commissurefeature 116 and ending with the connection between an end of strut 114 cand an end of strut 114 d.

As discussed above, the leaflets 108 may be attached directly to andsupported by the struts 114 a, 114 b, 114 c, 114 d, 114 e, and 114 f,and by commissure features 116, such as by suturing. In such event, thecuff 106 may perform little or no supportive function for the leaflets108. Hence, the cuff 106 is not subjected to high stresses and istherefore less likely to wear during use. In light of this, thethickness of the cuff may be reduced. Reducing the thickness of the cuff106 results in a decrease in the volume of the valve assembly 104 in thecollapsed condition. This decreased volume is desirable as it enablesthe prosthetic heart valve 100 to be implanted in a patient using adelivery device that is smaller in cross-section than conventionaldelivery devices. In addition, since the material forming the stentstruts 114 is generally stronger than the material forming the cuff 106,the stent struts 114 may perform the supportive function for theleaflets 108 better than the cuff 106.

In operation, the embodiments of the prosthetic heart valve 100described above may be used to replace a native heart valve, such as theaortic valve, a surgical heart valve or a heart valve that has undergonea surgical procedure. The prosthetic heart valve may be delivered to thedesired site (e.g., near a native aortic annulus) using any suitabledelivery device. During delivery, the prosthetic heart valve is disposedinside the delivery device in the collapsed condition. The deliverydevice may be introduced into a patient using a transfemoral,transapical, transseptal, transaxillary or other approach. Once thedelivery device has reached the target site, the user may deploy theprosthetic heart valve. Upon deployment, the prosthetic heart valveexpands into secure engagement within the native aortic annulus. Whenthe prosthetic heart valve is properly positioned inside the heart, itworks as a one-way valve, allowing blood to flow in one direction andpreventing blood from flowing in the opposite direction.

FIGS. 2A and 2B show an end view of a prosthetic heart valve 200 as seenfrom the downstream side of the valve assembly, e.g., looking from theaorta or aortic sinus toward the heart and the native valve annulus. Asseen in FIG. 2A, the valve assembly includes a stent 202 and valveleaflets 208 a, 208 b, and 208 c attached to the stent and to commissurefeatures 216 a, 216 b, and 216 c. At least one edge of each leaflet 208is sutured to the stent 202 and to two of the three commissure features216, leaving at least one edge free to move in response to the pumpingof blood. As the blood pressure in the left ventricle increases, thefree edges of the leaflets move away from one another to allow blood toflow from the left ventricle to the aorta, following which the freeedges move toward one another and coapt to prevent blood from flowingback from the aorta into the left ventricle.

Areas of actual contact between the coaptation sections of adjacentleaflets are referred to herein as the coaptation junctions of theleaflets and are illustrated in FIG. 2A at 211 a, 211 b, and 211 c. Thecoaptation section of each leaflet may range in size as a particularvalve design demands, but generally will be sufficient to provide sometolerance or ability to form a coaptation junction even if the shape ofthe valve is distorted during placement, as illustrated in FIG. 2B.

The annulus section of prosthetic heart valve 200 has a generallyregular cylindrical shape by which is meant that the structure has agenerally circular cross-section with a substantially constant diameteralong its length. When placed in the annulus of a native heart valve,such as, for example, the tricuspid aortic valve, and expanded, asubstantially fluid-tight fit should result. However, the native valveannulus may not be circular, and, in fact, may vary from patient topatient, as may the shape of the aortic sinus or aorta, the angle of thejunction between the valve annulus and the aortic sinus, and other localanatomical features. When prosthetic heart valve 200 is deployed andexpanded, it must accommodate these anatomical variations in order tofunction properly. This may result in a distortion in the shape of stent202 and/or valve assembly 204, and the repositioning of leaflets 208 a,208 b, and 208 c relative to one another, which can affect thecoaptation junctions 211 a, 211 b, and 211 c.

As the stent of a collapsible prosthetic heart valve distorts duringimplantation, during beating of the heart, or because of irregularitiesin the patient's anatomy or the condition of the native valve, suchdistortion may be translated to the valve assembly, such that not all ofthe valve leaflets meet to form effective coaptation junctions. This canresult in leakage or regurgitation and other inefficiencies which canreduce cardiac performance. Moreover, if the prosthetic valve is notplaced optimally and the valve leaflets are not coapting as intended,other long term effects, such as uneven wear of the individual leaflets,can be postulated.

As shown in FIG. 2B, ideally, valve leaflets 208 a, 208 b, and 208 cfully coapt despite the distortion of the annulus section (hidden behindthe valve leaflets in this figure) into a more elongated or ellipticalconfiguration. As will be appreciated, the distortion of the annulussection affects the relative positions of commissure features 216 a-c,as well as the positions of leaflets 208 a-c relative to one another.The ability of the valve leaflets 208 a-c to fully coapt despite thisdistortion enables prosthetic valve 200 to function in the mannerintended.

Less than ideal native valve geometry may increase the stresses oncertain portions of the prosthetic heart valve. FIG. 3 is a partial sideview of a prosthetic heart valve 300 having a stent 302 and a valveassembly 304 disposed in the annulus section 310 of the stent. Withinthe heart valve 300, leaflets 308 are attached to cuff 306 via sutures.Specifically, FIG. 3 shows the load distribution in the valve assembly.When leaflets 308 coapt to form a closed configuration, load istransferred from the leaflet structure to the leaflet-commissure featurejunction as indicated by “A”. The load distribution diagram shows thathigh point loads are generated at region “A” where the leaflets and/orthe cuff are joined to the commissure feature 316. If the point loads atregions “A” are sufficiently high, the leaflets may tear from thecommissure feature. Thus, regions A may be prone to wear. Moreover, ifloads are not properly distributed, the valve may wear at anotherlocation.

FIG. 4 is an enlarged top perspective view of a portion of thecollapsible prosthetic heart valve showing a possible location of wear.As seen from this view, at wear region W, the leaflet 408 may becomedetached from cuff 406. Such wear may occur by separation of the cuff406, the leaflet 408, the sutures attaching the leaflet to the cuff, orany combination thereof. Superior attachment of the leaflets to thecommissure features may better distribute stresses to the stentstructure, decreasing the likelihood of tissue or suture wear andimproving durability.

Features of this aspect of the present invention will be described inconnection with the commissure attachment feature 500 shown in FIG. 5.It will also be noted that while the inventions herein are predominantlydescribed with respect to a tricuspid valve and a stent having a shapeas illustrated in FIG. 1, the valve could be a bicuspid valve, such asthe mitral valve, and the stent could have different shapes, such as aflared or conical annulus section, a less-bulbous aortic section, andthe like, and a differently shaped transition section.

FIG. 5 illustrates a commissure feature 500 coupled to struts 514 forattaching a valve assembly to the stent. Commissure feature 500 may beformed of a body 502 having a proximal end 510 and a distal end 520.Body 502 may be generally trapezoidal near the proximal end 510 and mayinclude an oval portion near the distal end 520. Any number of eyelets504 may be provided in body 502, including one, two, three, four, fiveor six eyelets. Eyelets 504 may be disposed in rows or columns and maybe formed with the same or different shapes. Each pair of eyelets 504may be separated by a rib for attaching a suture to the commissurefeature 500. As shown in FIG. 5, commissure feature 500 has two eyelets,an upper eyelet 504 a and a lower eyelet 504 b, separated by a rib 506.

As seen in FIG.5, commissure feature 500 is coupled to four struts 514a-d, two of which converge at each end of the body 502. For example,struts 514 a and 514 b merge near the top of body 502. The meeting pointwhere two struts 514 merge is referred to as an ancon 512. Thus,commissure feature 500 includes two ancons 512, one at the top of body502 between struts 514 a and 514 b, and a second at the bottom of body502 between struts 514 c and 514 d.

Leaflets (not shown) may be attached to commissure feature 500 bypassing sutures through eyelets 504 and/or around struts 514. In thismanner, load may be distributed across the area of commissure feature500. Specifically, stress from the leaflets is distributed acrosssubstantially the entirety of area L1 of the commissure feature 500.Thus, commissure feature 500 is sized to be as large as practical so asto have a large area to distribute stress across, yet small enough toallow for the manufacture of a relatively short stent having as small acircumferential crimp profile as possible, while providing substantialflexibility during implantation.

The suture pattern attaching the leaflets to the commissure feature mayreduce the risk of failure of the valve. One example of such a suturepattern according to the present invention is illustrated in FIGS. 6A-C.FIG. 6A illustrates the leaflet-commissure feature combination as seenfrom the ablumenal side of a valve assembly, while FIG. 6B illustratesthe same combination as seen from the lumenal side of the valveassembly.

Each leaflet includes a tab 854 at each point at which the two edges ofthe leaflet intersect. These tabs 854 are used to join the leaflets tothe commissure features 500 of the stent. As seen in FIG. 6B, two tabs854 of two different leaflets 850 are attached to commissure feature 500using a single or multiple sutures. As described herein, a single sutureS attaches leaflets 850 to commissure feature 500. It will beunderstood, however, that multiple sutures may be used to attach theleaflets to the commissure feature. For example, one suture may attach afirst leaflet 850 to commissure feature 500, while a second, separatesuture attaches the second leaflet 850 to commissure feature 500.

The suture pattern and the order of attachment will be described withreference to FIG. 6C, which shows an enlarged view of theleaflet-commissure combination from the ablumenal side of the valveassembly and depicts the suture pattern through several positions p1-16on the assembly. It will be appreciated that FIG. 6B shows thecorresponding suture pattern from the lumenal side of the valve assemblyand that the suture pattern may be understood from this view as well.

The suture pattern may begin at any point at or near commissure feature500 and terminate at any other point. In at least some examples, thesuture pattern begins and terminates at the same position. For the sakeof illustration, the suture pattern will be described as beginning atpoint p1, within eyelet 504 b. As used herein, with reference to FIG. 6Cand other figures showing the ablumenal side of the assembly, the term“out” indicates passing the suture from the lumenal side of the valvethrough the leaflet tab 854 and past the stent structure to theablumenal side of the valve, while the term “in” indicates passing thesuture from the ablumenal side of the valve past the stent structure andthrough the leaflet tab 854 to the lumenal side of the valve.

The suture pattern may include two suture tails and may begin by passingthe first suture tail out through eyelet 504 b at point p1. Suture S maythen be advanced in through point p2 in eyelet 504 a, back out throughpoint p3 in eyelet 504 b and finally in through point p4 in eyelet 504a, essentially forming two loops of sutures around central rib 506. Asused herein, the term “central” is used generally to mean that the ribis disposed anywhere between two eyelets, and not at the midpoint.Suture S may then be directed to the distal end 520 of commissurefeature 500 and passed out through point p5 adjacent the inner edge ofstrut 514 b, and then in through point p6 located adjacent the outeredge of strut 514 b. The second tail of suture S may be directed to theproximal end 510 of commissure feature 500 and passed out through pointp7 adjacent the inner edge of strut 514 d, in through point p8 adjacentthe outer edge of strut 514 d, and back out through point p9 at or nearpoint p7 to leave a first free tail T1 extending from point p9. In atleast some examples, the inner diameter and outer diameter areasymmetric.

Using the first suture tail, previously at point p6, suture S may bemaneuvered toward strut 514 a and passed out through point p10 adjacentthe outer edge of strut 514 a, around the strut, and then in throughpoint p11 adjacent the inner edge of strut 514 a. Suture S may then bedirected toward rib 506 and passed out through point p12 in eyelet 504a, in through point p13 in eyelet 504 b, back out through point p14 ineyelet 504 a, and in again through point p15 in eyelet 504 b, formingtwo additional loops around central rib 506. From point p15, suture Smay be directed to the proximal end 570 of commissure feature 500 andpassed out through point p16 adjacent the inner edge of strut 514 c, inthrough point p17 adjacent the outer edge of strut 514 c, and out againthrough point p18 located at or near point p16 to form a loop aroundstrut 514 c and leave a second free tail T2 extending from point p18.Suture S may then be secured by knotting or tying the free tails T1 andT2 together near points p9 and p18 to complete the attachment ofleaflets 850 to the commissure feature 500.

As seen in FIG. 6C, one advantage of using commissure attachment feature500 is that it allows attachments above and/or below the commissurefeature at struts 514 a-d. Sutures that wrap around struts 514 a-d maybe wrapped at or near ancons 512. The ability to apply sutures aroundstruts 514 at or near ancons 512 affords a degree of flexibility andcompliance in the overall attachment scheme while still effecting asecure attachment of the leaflets 850 to the commissure feature 500.Thus, the attachment of the leaflets 850 to commissure attachmentfeature 505 is not limited to eyelets 504. As is evident from FIG. 6C,the final suture pattern may be symmetric about a central axis passingthrough body 502 between struts 514 a and 514 b on the distal end 520 ofthe body and between struts 514 c and 514 d on the proximal end 510 ofthe body.

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims.

It will be appreciated that the various dependent claims and thefeatures set forth therein can be combined in different ways thanpresented in the initial claims. It will also be appreciated that thefeatures described in connection with individual embodiments may beshared with others of the described embodiments.

The invention claimed is:
 1. A prosthetic heart valve, comprising: acollapsible and expandable stent having a proximal end, a distal end, anannulus section adjacent the proximal end and an aortic section adjacentthe distal end, the stent including a plurality of struts; a pluralityof commissure features disposed on the stent and coupled to selectedones of the struts, each commissure feature including a body having aproximal end adjacent the annulus section and a distal end adjacent theaortic section, and at least one eyelet in the body, the body beingcoupled to upper struts near the aortic section; and a collapsible andexpandable valve assembly, including a plurality of leaflets, at leastone of the leaflets being connected to the at least one eyelet and to atleast one of the upper struts via a suture pattern, wherein the strutsfurther include two lower struts coupled to the proximal end of thebody, and the at least one leaflet is further connected to the two lowerstruts.
 2. The prosthetic heart valve of claim 1, wherein two leafletsare connected to each commissure feature.
 3. The prosthetic heart valveof claim 1, wherein the suture pattern is symmetrical about a centralaxis passing through the body between the proximal and distal ends ofthe body.
 4. The prosthetic valve of claim 1, wherein the suture patternfurther includes two tails knotted together adjacent one of the upperstruts and the lower struts.
 5. A prosthetic heart valve, comprising: acollapsible and expandable stent having a proximal end, a distal end, anannulus section adjacent the proximal end and an aortic section adjacentthe distal end, the stent including a plurality of struts; a pluralityof commissure features disposed on the stent and coupled to selectedones of the struts, each commissure feature including a body having aproximal end adjacent the annulus section and a distal end adjacent theaortic section, and at least one eyelet in the body, the body beingcoupled to upper struts near the aortic section; and a collapsible andexpandable valve assembly, including a plurality of leaflets, at leastone of the leaflets being connected to the at least one eyelet and to atleast one of the upper struts via a suture pattern; wherein each bodyhas two eyelets and a central rib formed between the two eyelets, andwherein the suture pattern includes loops of suture around the centralrib.
 6. The prosthetic heart valve of claim 5, wherein the suturepattern includes four loops of suture around the central rib.
 7. Theprosthetic heart valve of claim 5, wherein the suture pattern begins bybeing coupled to the central rib, then a first of the upper struts, thena first of the lower struts, then a second of the upper struts, then thecentral rib a second time, and then a second of the lower struts.
 8. Amethod of assembling a prosthetic heart valve, comprising: providing acollapsible and expandable stent having a proximal end, a distal end, anannulus section adjacent the proximal end and an aortic section adjacentthe distal end, the stent including a plurality of struts and aplurality of commissure features disposed on the stent and coupled toupper struts adjacent the aortic section, each commissure featureincluding a body having a proximal end adjacent the annulus section anda distal end adjacent the aortic section, and at least one eyelet in thebody, the body being coupled to upper struts near the distal end of thebody, and to two lower struts near the proximal end of the body; andcoupling a collapsible and expandable valve assembly to the stent, thevalve assembly including a plurality of leaflets, and the coupling stepincluding connecting at least one of the leaflets to the at least oneeyelet and to at least one of the upper struts via a suture pattern;wherein the coupling step includes connecting the at least one leafletto the two lower struts.
 9. The method of claim 8, wherein the couplingstep includes connecting two leaflets to each commissure feature. 10.The method of claim 8, wherein the coupling step includes coupling theat least one leaflet to the body using a suture pattern that issymmetrical about a central axis passing through.
 11. A method ofassembling a prosthetic heart valve, comprising: providing a collapsibleand expandable stent having a proximal end, a distal end, an annulussection adjacent the proximal end and an aortic section adjacent thedistal end, the stent including a plurality of struts and a plurality ofcommissure features disposed on the stent and coupled to upper strutsadjacent the aortic section, each commissure feature including a bodyhaving a proximal end adjacent the annulus section and a distal endadjacent the aortic section, and at least one eyelet in the body, thebody being coupled to upper struts near the distal end of the body; andcoupling a collapsible and expandable valve assembly to the stent, thevalve assembly including a plurality of leaflets, and the coupling stepincluding connecting at least one of the leaflets to the at least oneeyelet and to at least one of the upper struts via a suture; whereineach body has two eyelets and a central rib formed between the twoeyelets, and wherein the suture pattern includes loops of suture aroundthe central rib.
 12. The method of claim 11, wherein the suture patternincludes four loops of suture around the central rib.